Billed as the "world's first subway-responsive light sculpture," Lightrail would "transform San Francisco’s main artery into a scene of wonder and awe for millions—while highlighting the crucial importance of public transit for the future of our cities in a beautiful and compelling way."

Strings of 20,000 LED lights would be suspended from the overhead Muni lines along 2.1 miles of Market Street. By hooking into realtime BART and Muni data, pulses of colored light would travel down Market Street in sync with the movement of the trains below.

And when Muni and BART have stopped running, "randomly distributed small pulses of light will move along Market Street, simulating the passage of pedestrians. The piece will thus be a celebration of the many sustainable modes of transit that make up city life."

The privately-funded Lightrail is being presented by Illuminate the Arts, the same folks behind the popular Bay Lights installation on the Bay Bridge.  The project received preliminary approval from the SF Arts Commission in December, and is now winding its way through various city agencies.

One such agency is the Historic Preservation Commission. To power the lights, Lightrail's sponsors hope to affix utility boxes to a series of 83 ornate lampposts called the Path Of Gold Standards, which have historical landmark status. A committee of the Historic Preservation Commission will be considering the project this Wednesday. 

Assuming all such issues get resolved, Lightrail could be installed later this year.  The project is only meant to be temporary though; it would be dismantled some time in 2018.

We'll keep an eye on this one, and will update if the project should get the green light (pun intended).